Ceramic insulator and methods of use and manufacture thereof

ABSTRACT

One embodiment of the present disclosure is directed to an insulator comprising a ceramic composition, wherein the ceramic composition comprises about 25-60% SiO 2 ; 15-35% R 2 O 3 , wherein the R 2 O 3  is 3-15% B 2 O 3  and 5-25% Al 2 O 3 ; 4-25% MgO+0-7% Li 2 O, wherein the total of MgO+Li 2 O is between about 6-25%; 2-20% R 2 O, wherein the R 2 O is 0-15% Na 2 O, 0-15% K 2 O, 0-15% Rb 2 O; 0-15% Rb 2 O; 0-20% Cs 2 O; and 4-20% F; crystalline grains, wherein the crystalline grains are substantially oriented to extend in a first direction to provide improved insulating properties in a direction perpendicular to the first direction, wherein the first direction is circumferential and the direction perpendicular to the first direction is radial; and a first zone and a second zone, wherein the first zone is in compression and the second zone is in tension.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims priority to and the benefit of U.S.Provisional Application No. 61/237,425, filed Aug. 27, 2009 and titledOXYGENATED FUEL PRODUCTION; U.S. Provisional Application No. 61/237,466,filed Aug. 27, 2009 and titled MULTIFUEL MULTIBURST; U.S. ProvisionalApplication No. 61/237,479, filed Aug. 27, 2009 and titled FULL SPECTRUMENERGY; PCT Application No. PCT/US09/67044, filed Dec. 7, 2009 andtitled INTEGRATED FUEL INJECTORS AND IGNITERS AND ASSOCIATED METHODS OFUSE AND MANUFACTURE; U.S. Provisional Application No. 61/304,403, filedFeb. 13, 2010 and titled FULL SPECTRUM ENERGY AND RESOURCE INDEPENDENCE;and U.S. Provisional Application No. 61/312,100, filed Mar. 9, 2010 andtitled SYSTEM AND METHOD FOR PROVIDING HIGH VOLTAGE RF SHIELDING, FOREXAMPLE, FOR USE WITH A FUEL INJECTOR. The present application is acontinuation-in-part of U.S. patent application Ser. No. 12/653,085,filed Dec. 7, 2009 and titled INTEGRATED FUEL INJECTORS AND IGNITERS ANDASSOCIATED METHODS OF USE AND MANUFACTURE; which is acontinuation-in-part of U.S. patent application Ser. No. 12/006,774 (nowU.S. Pat. No. 7,628,137), filed Jan. 7, 2008 and titled MULTIFUELSTORAGE, METERING, AND IGNITION SYSTEM; and which claims priority to andthe benefit of U.S. Provisional Application No. 61/237,466, filed Aug.27, 2009 and titled MULTIFUEL MULTIBURST. The present application is acontinuation-in-part of U.S. patent application Ser. No. 12/581,825,filed Oct. 19, 2009 and titled MULTIFUEL STORAGE, METERING, AND IGNITIONSYSTEM; which is a divisional of U.S. patent application Ser. No.12/006,774 (now U.S. Pat. No. 7,628,137), filed Jan. 7, 2008 and titledMULTIFUEL STORAGE, METERING, AND IGNITION SYSTEM. Each of theseapplications is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The following disclosure relates generally to improved materialsincluding improved dielectric insulators.

BACKGROUND

It has long been desired to interchangeably use methane, hydrogen ormixtures of methane and hydrogen as cryogenic liquids or compressedgases in place of gasoline in spark-ignited engines. But this goal hasnot been satisfactorily achieved, and as a result, the vast majority ofmotor vehicles remain dedicated to petrol even though the costs ofmethane and many forms of renewable hydrogen are far less than gasoline.Similarly it has long been a goal to interchangeably use methane,hydrogen or mixtures of methane and hydrogen as cryogenic liquids and/orcompressed gases in place of diesel fuel in compression-ignited enginesbut this goal has proven even more elusive, and most diesel enginesremain dedicated to pollutive and more expensive diesel fuel.

Conventional spark ignition systems include a high voltage but lowenergy ionization of a mixture of air and fuel. Conventional sparkenergy magnitudes of about 0.05 to 0.15 joule are typical for normallyaspirated engines equipped with spark plugs that operate withcompression ratios of 12:1 or less. Adequate voltage to produce suchionization must be increased with higher ambient pressure in the sparkgap. Factors requiring higher voltage include leaner air-fuel ratios anda wider spark gap as may be necessary for ignition, increases in theeffective compression ratio, supercharging, and reduction of the amountof impedance to air entry into a combustion chamber. Conventional sparkignition systems fail to provide adequate voltage generation todependably provide spark ignition in engines such as diesel engines withcompression ratios of 16:1 to 22:1 and often fail to provide adequatevoltage for unthrottled engines that are supercharged for purposes ofincreased power production and improved fuel economy. These issues alsoplague alternative or mixed fuel engines.

Failure to provide adequate voltage at the spark gap is most often dueto inadequate dielectric strength of ignition system components such asthe spark plug porcelain and spark plug cables. High voltage applied toa conventional spark plug, which essentially is at the wall of thecombustion chamber, causes heat loss of combusting homogeneous air-fuelmixtures that are at and near all surfaces of the combustion chamberincluding the piston, cylinder wall, cylinder head, and valves. Suchheat loss reduces the efficiency of the engine and may degrade thecombustion chamber components that are susceptible to oxidation,corrosion, thermal fatigue, increased friction due to thermal expansion,distortion, warpage, and wear due to loss of viability of overheated oroxidized lubricating films.

In addition, modern engines lack electrical insulation components havingsufficient dielectric strength and durability for protecting componentsthat must withstand cyclic applications of high voltage, coronadischarges, and superimposed degradation due to shock, vibration, andrapid thermal cycling to high and low temperatures. Similarly, thecombustion chamber of a modern diesel engine is designed with very smalldiameter ports for a “pencil” type direct fuel injector that must fitwithin the complex and tightly crowded inlet and exhaust valve operatingmechanisms of a typical overhead valve engine head. A typical dieselfuel injector's port diameter for entry into the combustion chamber islimited to about 8.4 mm (0.331″). In addition to such severe spacelimitations, the hot lubricating oil is constantly splashed in theengine head environment within the valve cover to heat the fuel injectorassembly to more than 115° C. (240° F.) for most of the million-milelife requirement, which prohibits application of conventional air-cooledsolenoid valve designs.

It is highly desirable to overcome requirements that limit diesel engineoperation to compression ignition and the use of diesel fuel of a narrowcetane rating and viscosity along with strict requirements forelimination of particles and water. The potential exists for moreplentiful fuel selections with far less replacement cost wherein thefuels have a wide variation in cetane and/or octane ratings along withimpurities such as water, nitrogen, carbon dioxide carbon monoxide, andvarious particulates.

In order to provide smooth transition from economic dependence uponfossil fuels is highly desirable to enable interchangeable utilizationof conventional diesel fuel or gasoline along with renewable fuels suchas hydrogen, methane, or fuel alcohols. Improved insulators are requiredin instances that diesel fuel is to be utilized by application ofsufficient plasma energy to the diesel fuel as it enters the combustionchamber to cause very rapid evaporation and cracking or subdivision ofdiesel fuel molecules, and production of ignition ions to thus overcomethe formidable problems and limitations of compression ignition.

Accordingly, there is a need in the art for improved insulators andmaterials and method of manufacture and use, for example, materials withimproved durability and dielectric strength for use in ignition systemcomponents for multifuel engines.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional side view of an integratedinjector/igniter configured in accordance with an embodiment of thedisclosure.

FIG. 2 is a cross-sectional side partial view of an injector configuredin accordance with an embodiment of the disclosure.

FIG. 3A is a side view of an insulator or dielectric body configured inaccordance with one embodiment of the disclosure, and FIG. 3B is across-sectional side view taken substantially along the lines 3B-3B ofFIG. 3A.

FIGS. 4A and 4B are cross-sectional side views taken substantially alongthe lines 4-4 of FIG. 2 illustrating an insulator or dielectric bodyconfigured in accordance with another embodiment of the disclosure.

FIGS. 5A and 5B are schematic illustrations of systems for forming aninsulator or dielectric body with compressive stresses in desired zonesaccording to another embodiment of the disclosure.

FIG. 6 is a schematic cross-sectional side view of an injector/igniterconfigured in accordance with an embodiment of the disclosure.

FIGS. 6A and 6B are cross-sectional side views of the body 602 of FIG. 6illustrating an insulator or dielectric body configured in accordancewith another embodiment of the disclosure.

DETAILED DESCRIPTION

The present application incorporates by reference in their entirety thesubject matter of each of the following U.S. patent applications, filedconcurrently herewith on Jul. 21, 2010 and titled: INTEGRATED FUELINJECTORS AND IGNITERS AND ASSOCIATED METHODS OF USE AND MANUFACTURE(Attorney Docket No. 69545-8031US); FUEL INJECTOR ACTUATOR ASSEMBLIESAND ASSOCIATED METHODS OF USE AND MANUFACTURE (Attorney Docket No.69545-8032US); INTEGRATED FUEL INJECTORS AND IGNITERS WITH CONDUCTIVECABLE ASSEMBLIES (Attorney Docket No. 69545-6033US); SHAPING A FUELCHARGE IN A COMBUSTION CHAMBER WITH MULTIPLE DRIVERS AND/OR IONIZATIONCONTROL (Attorney Docket No. 69545-8034US); METHOD AND SYSTEM OFTHERMOCHEMICAL REGENERATION TO PROVIDE OXYGENATED FUEL, FOR EXAMPLE,WITH FUEL-COOLED FUEL INJECTORS (Attorney Docket No. 89545-8037US); andMETHODS AND SYSTEMS FOR REDUCING THE FORMATION OF OXIDES OF NITROGENDURING COMBUSTION IN ENGINES (Attorney Docket No. 69545-8038US).

In order to fully understand the manner in which the above-reciteddetails and other advantages and objects according to the invention areobtained, a more detailed description of the invention will be renderedby reference to specific embodiments thereof.

Certain details are set forth in the following description and Figuresto provide a thorough understanding of various embodiments of thedisclosure. However, other details describe well-known structures andsystems. It will be appreciated that several of the details set forthbelow are provided to describe the following embodiments in a mannersufficient to enable a person skilled in the relevant art to make anduse the disclosed embodiments. Several of the details and advantagesdescribed below, however, may not be necessary to practice certainembodiments of the disclosure. Many of the details, dimensions, angles,shapes, and other features shown in the Figures are merely illustrativeof particular embodiments of the disclosure. Accordingly, otherembodiments can have other details, dimensions, angles, and featureswithout departing from the spirit or scope of the present disclosure. Inaddition, those of ordinary skill in the art will appreciate thatfurther embodiments of the disclosure can be practiced without severalof the details described below.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the present disclosure. Thus, theoccurrences of the phrases “in one embodiment” or “in an embodiment” invarious places throughout this specification are not necessarily allreferring to the same embodiment. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments. The headings provided herein are forconvenience only and do not interpret the scope or meaning of theclaimed disclosure.

FIG. 1 is a schematic cross-sectional side view of an integratedinjector/igniter 110 (“injector 110”) configured in accordance with anembodiment of the disclosure. The injector 110 illustrated in FIG. 1 isconfigured to inject different fuels into a combustion chamber 104 andto adaptively adjust the pattern and/or frequency of the fuel injectionsor bursts based on combustion properties and conditions in thecombustion chamber 104. As explained in detail below, the injector 110can optimize the injected fuel for rapid ignition and completecombustion. In addition to injecting the fuel, the injector 110 includesone or more integrated ignition features that are configured to ignitethe injected fuel. As such, the injector 110 can be utilized to convertconventional internal combustion engines to be able to operate onmultiple different fuels.

According to one aspect of the illustrated embodiment, at least aportion of the body 112 is made from one or more dielectric materials117 suitable to enable the high-energy ignition to combust differentfuels, including unrefined fuels or low energy density fuels. Thesedielectric materials 117 can provide sufficient electrical insulation ofthe high voltage for the production, isolation, and/or delivery of sparkor plasma for ignition. In certain embodiments, the body 112 can be madefrom a single dielectric material 117. In other embodiments, however,the body 112 can include two or more dielectric materials. For example,at least a segment of the middle portion 116 can be made from a firstdielectric material having a first dielectric strength, and at least asegment of the nozzle portion 118 can be made from a dielectric materialhaving a second dielectric strength that is greater than the firstdielectric strength. With a relatively strong second dielectricstrength, the second dielectric material can protect the injector 110from thermal and mechanical shock, fouling, voltage tracking, etc.Examples of suitable dielectric materials, as well as the locations ofthese materials on the body 112, are described in detail below.

Dielectric Features

In one aspect, FIG. 2 is a cross-sectional side partial view of aninjector 210. The injector 210 shown in FIG. 2 illustrates severalfeatures of the dielectric materials that can be used according toseveral embodiments of the disclosure. The illustrated injector 210includes several features that can be at least generally similar instructure and function to the corresponding features of the injectorsdescribed above with reference to FIG. 1. For example, the injector 210includes a body 212 having a nozzle portion 218 extending from a middleportion 216. The nozzle portion 218 extends into an opening or entryport 209 in the engine head 207. Many engines, such as diesel engines,have entry ports 209 with very small diameters (e.g., approximately 7.09mm or 0.279 inch in diameter). Such small spaces present the difficultyof providing adequate insulation for spark or plasma ignition of fuelspecies contemplated by the present disclosure (e.g., fuels that areapproximately 3,000 times less energy dense than diesel fuel). However,and as described in detail below, injectors of the present disclosurehave bodies 212 with dielectric or insulative materials that can providefor adequate electrical insulation for ignition wires to produce therequired high voltage (e.g., 60,000 volts) for production, isolation,and/or delivery of ignition events (e.g., spark or plasma) in very smallspaces. These dielectric or insulative materials are also configured forstability and protection against oxidation or other degradation due tocyclic exposure to high temperature and high-pressure gases produced bycombustion. Moreover, as explained in detail below, these dielectricmaterials can be configured to integrate optical or electricalcommunication pathways from the combustion chamber to a sensor, such asa transducer, instrumentation, filter, amplifier, controller, and/orcomputer. Furthermore, the insulative materials can be brazed ordiffusion bonded at a seal location with a metal base portion 214 of thebody 212.

Spiral Wound Dielectric Features

According to another aspect of the body 212 of the injector 210illustrated in FIG. 2, the dielectric materials comprising the middleportion 216 and/or nozzle portion 218 of the injector 210 areillustrated in FIGS. 3A and 3B. More specifically, FIG. 3A is a sideview of an insulator or dielectric body 312, and FIG. 3B is across-sectional side view taken substantially along the lines 3B-3B ofFIG. 3A. Although the body 312 illustrated in FIG. 3A has a generallycylindrical shape, in other embodiments the body 312 can include othershapes, including, for example, nozzle portions extending from the body312 toward a combustion chamber interface 331. Referring to FIGS. 3A and3B together, in the illustrated embodiment the dielectric body 312 iscomposed of a spiral or wound base layer 328. In certain embodiments,the base layer 328 can be artificial or natural mica (e.g., pinhole freemica paper). In other embodiments, however, the base layer 328 can becomposed of other materials suitable for providing adequate dielectricstrength associated with relatively thin materials. In the illustratedembodiment, one or both of the sides of the base layer 328 are coveredwith a relatively thin dielectric coating layer 330. The coating layer330 can be made from a high-temperature, high-purity polymer, such asTeflon NXT, Dyneon TFM, Parylene HT, Polyethersulfone, and/orPolyetheretherketone. In other embodiments, however, the coating layer330 can be made from other materials suitable for adequately sealing thebase layer 328.

The base layer 328 and coating layer 330 can be tightly wound into aspiral shape forming a tube thereby providing successive layers ofsheets of the combined base layer 328 and coating layer 330. In certainembodiments, these layers can be bonded in the wound configuration witha suitable adhesive (e.g., ceramic cement). In other embodiments, theselayers can be impregnated with a polymer, glass, fumed silica, or othersuitable materials to enable the body 312 to be wrapped in the tightlywound tube shape. Moreover, the sheets or layers of the body 312 can beseparated by successive applications of dissimilar films. For example,separate films between layers of the body 312 can include Parylene N,upon Parylene C upon Parylene HT film layers, and/or layers separated byapplications of other material selections such as thin boron nitride,polyethersulfone, or a polyolefin such as polyethylene, or othersuitable separating materials. Such film separation may also beaccomplished by temperature or pressure instrumentation fibersincluding, for example, single-crystal sapphire fibers. Such fibers maybe produced by laser heated pedestal growth techniques, and subsequentlybe coated with perfluorinated ethylene propylene (FEP) or othermaterials with similar index of refraction values to prevent leakage ofenergy from the fibers into potentially absorbing films that surroundsuch fibers.

When the coating layer 330 is applied in relatively thin films (e.g.,0.1 to 0.3 mm), the coating layer 330 can provide approximately 2.0 to4.0 KVolts/0.001″ dielectric strength from −30° C. (e.g., −22° F.) up toabout 230° C. (e.g., 450° F.). The inventor has found that coatinglayers 330 having a greater thickness may not provide sufficientinsulation to provide the required voltage for ignition events. Morespecifically, as reflected in Table 1 below, coating layers with greaterthickness have remarkably reduced dielectric strength. These reduceddielectric strengths may not adequately prevent arc-through and currentleakage of the insulative body 312 at times that it is desired toproduce the ignition event (e.g., spark or plasma) at the combustionchamber. For example, in many engines with high compression pressures,such as typical diesel or supercharged engines, the voltage required toinitiate an ignition event (e.g., spark or plasma) is approximately60,000 volts or more. A conventional dielectric body including a tubularinsulator with only a 0.040 inch or greater effective wall thicknessthat is made of a conventional insulator may only provide 500Volts/0.001″ and will fail to adequately contain such required voltage.

TABLE 1 Dielectric Strength Comparisons of Selected FormulationsDielectric Strength Dielectric Strength (KV/mil) (KV/mil) (<0.06 mm(>1.0 mm Substance or 0.002″ films) or 0.040″) Teflon NXT 2.2-4.0KV/.001″   0.4-0.5 KV/.001″  Polyimide (Kapton)   7.4 KV/.001″  —Parylene (N, C, D, HT) 4.2-7.0 KV/.001″  — Dyneon TFM 2.5-3.0 KV/.001″  0.4-0.5 KV/.001″  CYTOP perflu- 2.3-2.8 KV/0.001″ — oropolymer Sapphire1.3-1.4 KV/0.001″   1.2 KV/0.001″ (Single-Crystal) Mica 2.0-4.5KV/0.001″ 1.4-1.9 KV/0.001″ Boron Nitride   1.6 KV/0.001″   1.4KV/0.001″ PEEK 3.0-3.8 KV/0.001″ 0.3-0.5 KV/0.001″ Polyethersulfone4.0-4.2 KV/0.001″ 0.3-0.5 KV/0.001″ Silica Quartz 1.1-1.4 KV/0.001″1.1-1.4 KV/0.001″

The embodiment of the insulator body 312 illustrated in FIGS. 3A and 3Bcan provide a dielectric strength of approximately 3,000 Volts/0.001″ attemperatures ranging from −30° C. (e.g., −22° F.) up to approximately450° C. (e.g., 840° F.). Moreover, the coating layers 330 can also serveas a sealant to the base layer 328 to prevent combustion gases and/orother pollutants from entering the body 312. The coating layers 330 canalso provide a sufficiently different index of refraction to improve theefficiency of light transmission through the body 312 for opticalcommunicators extending through the body 312.

According to another feature of the illustrated embodiment, the body 312includes multiple communicators 332 extending longitudinally through thebody 312 between sheets or layers of the base layers 328. In certainembodiments, the communicators 332 can be conductors, such as highvoltage spark ignition wires or cables. These ignition wires can be madefrom metallic wires that are insulated or coated with oxidized aluminumthereby providing alumina on the wires. Because the communicators 332extend longitudinally through the body 312 between corresponding baselayers 328, the communicators 332 do not participate in any chargeextending radially outwardly through the body 312. Accordingly, thecommunicators 332 do not affect or otherwise degrade the dielectricproperties of the body 312. In addition to delivering voltage forignition, in certain embodiments the communicators 332 can also beoperatively coupled to one or more actuators and/or controllers to drivea flow valve for the fuel injection.

In other embodiments, the communicators 332 can be configured totransmit combustion data from the combustion chamber to one or moretransducers, amplifiers, controllers, filter, instrumentation computer,etc. For example, the communicators 332 can be optical fibers or othercommunicators formed from optical layers or fibers such as quartz,aluminum fluoride, ZBLAN fluoride, glass, and/or polymers, and/or othermaterials suitable for transmitting data through an injector. In otherembodiments, the communicators 332 can be made from suitabletransmission materials such as Zirconium, Barium, Lanthanum, Aluminum,and Sodium Fluoride (ZBLAN), as well as ceramic or glass tubes.

Grain Orientation of Dielectric Features

Referring again to FIG. 2, according to another embodiment of theinjector 210 illustrated in FIG. 2 the dielectric materials of the body212 (e.g., the middle portion 216 and/or the nozzle portion 218) may beconfigured to have specific grain orientations to achieve desireddielectric properties capable of withstanding the high voltagesassociated with the present disclosure. For example, the grain structurecan include crystallized grains that are aligned circumferentially, aswell as layered around the tubular body 212, thereby forming compressiveforces at the exterior surface that are balanced by subsurface tension.More specifically, FIGS. 4A and 4B are cross-sectional side views of adielectric body 412 configured in accordance with another embodiment ofthe disclosure and taken substantially along the lines 4-4 of FIG. 2.Referring first to FIG. 4A, the body 412 can be made of a ceramicmaterial having a high dielectric strength, such as quartz, sapphire,glass matrix, and/or other suitable ceramics.

As shown in the illustrated embodiment, the body 412 includescrystalline grains 434 that are oriented in generally the samedirection. For example, the grains 434 are oriented with each individualgrain 434 having its longitudinal axis aligned in the directionextending generally circumferentially around the body 412. With thegrains 434 layered in this orientation, the body 412 provides superiordielectric strength in virtually any thickness of the body 412. This isbecause the layered long, flat grains do not provide a good conductivepath radially outwardly from the body 412.

FIG. 4B illustrates compressive forces in specific zones of the body412. More specifically, according to the embodiment illustrated in FIG.4B, the body 412 has been treated to at least partially arrange thegrains 434 in one or more compressive zones 435 (i.e., zones includingcompressive forces according to the orientation of the grains 434)adjacent to an outer exterior surface 437 and an inner exterior surface438 of the body 412. The body 412 also includes a non-compressive zone436 of grains 434 between the compressive zones 435. The non-compressivezone 436 provides balancing tensile forces in a middle portion of thebody 412. In certain embodiments, each of the compressive zones 435 caninclude more grains 434 per volume to achieve the compressive forces. Inother embodiments, each of the compressive zones 435 can include grains434 that have been influenced to retain locally amorphous structures, orthat have been modified by the production of an amorphous structure orcrystalline lattice that has less packing efficiency than the grains 434of the non-compressive zone 436. In still further embodiments, the outersurface 437 and the inner surface 438 can be caused to be in compressionas a result of ion implantation, sputtered surface layers, and/ordiffusion of one or more substances into the surface such that thesurface has a lower packing efficiency that the non-compressive zone 436of the body 412. In the embodiment illustrated in FIG. 4B, thecompressive zones 435 at the outside surface 437 and the inner surface438 of the body 412 provide a higher anisotropic dielectric strength.

One benefit of the embodiment illustrated in FIG. 4B is that as a resultof this difference in packing efficiency in the compressive zones 435and the non-compressive zone 436, the surface in compression is causedto be in compression and becomes remarkably more durable and resistantto fracture or degradation. For example, such compressive forcedevelopment at least partially prevents entry of substances (e.g.,electrolytes such as water with dissolved substances, carbon richmaterials, etc.) that could form conductive pathways in the body 412thereby reducing the dielectric strength of the body 412. Suchcompressive force development also at least partially preventsdegradation of the body 412 from thermal and/or mechanical shock fromexposure to rapidly changing temperatures, pressures, chemicaldegradants, and impulse forces with each combustion event. For example,the embodiment illustrated in FIG. 4B is configured specifically forsustained voltage containment of the body 412, increased strengthagainst fracture due to high loading forces including point loading, aswell as low or high cycle fatigue forces.

Another benefit of the oriented crystalline grains 434 combined with thecompressive zones 435, is that this configuration of the grains 434provides maximum dielectric strength for containing voltage that isestablished across the body 412. For example, this configurationprovides remarkable dielectric strength improvement of up to 2.4KV/0.001 inch in sections that are greater than 1 mm or 0.040 inchthick. These are significantly higher values compared to the sameceramic composition without such new grain characterization with onlyapproximately 1.0 to 1.3 KV/0.001 inch dielectric strength.

Several processes for producing insulators described above withcompressive surface features are described in detail below. In oneembodiment, for example, an insulator configured in accordance with anembodiment of the disclosure can be made from materials disclosed byU.S. Pat. No. 3,689,293, which is incorporated herein in its entirety byreference. For example, an insulator can be made from a materialincluding the following ingredients by weight: 25-60% SiO₂, 15-35% R₂O₃(where R₂O₃ is 3-15% B₂O₃ and 5-25% Al₂O₃), 4-25% MgO+0-7% Li₂O (withthe total of MgO+Li₂O being between about 6-25%), 2-20% R₂O (where R₂Ois 0-15% Na₂O, 0-15% K₂O, 0-15% Rb₂O), 0-15% Rb₂O, 0-20% Cs₂O, and with4-20% F. More specifically, in one embodiment, an illustrative formulaconsists of 43.9% SiO₂, 13.8% MgO, 15.7% Al₂O₃, 10.7% K₂O, 8.1% B₂O₃,and 7.9% F. in other embodiments, however, insulators configured inaccordance with embodiments of the disclosure can be made from greateror lesser percentages of these constituent materials, as well asdifferent materials.

According to one embodiment of the disclosure, the ingredientsconstituting the insulator are ball milled and fused in a suitableclosed crucible that has been made impervious and non-reactive to theformula of the constituent ingredients forming the insulator. Theingredients are held at approximately 1400° C. (e.g., 2550° F.) for aperiod that assures thorough mixing of the fused formula. The fused massis then cooled and ball milled again, along with additives that may beselected from the group including binders, lubricants, and firing aids.The ingredients are then extruded in various desired shapes including,for example, a tube, and heated to about 800° C. (1470° F.) for a timeabove the transformation temperature. Heating above the transformationtemperature stimulates fluoromica crystal nucleation. The extrudedingredients can then be further heated and pressure formed or extrudedat about 850-1100° C. (1580-2010° F.). This secondary heating causescrystals that are being formed to become shaped as generally describedabove for maximizing the dielectric strength in preferred directions ofthe resulting product.

Crystallization of such materials, including, for example, mica glassesincluding a composition of K₂Mg₅Si₈O₂₀F₄, produces an exothermic heatrelease as the volumetric packing efficiency of the grains increases andthe corresponding density increases. Transformation activity, such asnucleation, exothermic heat release rate, characterization of thecrystallization, and temperature of the crystallization, is a functionof fluorine content and or B₂O₃ content of the insulator. Accordingly,processing the insulator with control of these variables enablesimprovements in the yield, tensile, fatigue strength, and/or dielectricstrength, as well as increasing the chemical resistance of theinsulator.

This provides an important new anisotropic result of maximum dielectricstrength as may be designed and achieved by directed forming includingextruding a precursor tube into a smaller diameter or thinner walledtubing to produce elongated and or oriented crystal grains typical tothe representational population that are formed and layered to more orless surround a desired feature such as an internal diameter that isproduced by conforming to a mandrel that is used for accomplishing suchhot forming or extrusion.

According to another embodiment, a method of at least partiallyorienting and/or compressing the grains 434 of FIGS. 4A/B according tothe illustrated embodiment may be achieved by the addition of B₂O₃and/or fluorine to surfaces that are desired to become compressivelystressed against balancing tensile stresses in the substrate of formedand heat-treated products. Such addition of B₂O₃, fluorine, or similarlyactuating agents may be accomplished in a manner similar to dopants thatare added and diffused into desired locations in semiconductors. Theseactuating agents can also be applied as an enriched formula of thecomponent formula that is applied by sputtering, vapor deposition,painting, and/or washing. Furthermore, these actuating agents by beproduced by reactant presentation and condensation reactions.

Increased B₂O₃ and/or fluorine content of material at and near thesurfaces that are desired to become compressively loaded causes morerapid nucleation of fluoromica crystals. This nucleation causes agreater number of smaller crystals to compete with diffusion addedmaterial in comparison with non-compressive substrate zones of theformula. This process accordingly provides for a greater packingefficiency in the non-compressive substrate zones than in thecompressive zones closer to the surfaces that have received enrichmentwith B₂O₃, fluorine, and/or other actuating agents that produce theadditional nucleation of fluoromica crystals. As a result, the desirablesurface compression preloading strengthens the component againstignition events and chemical agents.

According to another method of producing or enhancing compressive forcesthat are balanced by tensile forces in corresponding substrates includesheating the target zone to be placed in compression. The target zone canbe sufficiently heated to re-solution the crystals as an amorphousstructure. The substrate can then be quenched to sufficiently retainsubstantial portions of the amorphous structure. Depending upon the typeof components involved, such heating may be in a furnace. Such heatingmay also be by radiation from a resistance or induction heated source,as well as by an electron beam or laser. Another variation of thisprocess is to provide for increased numbers of smaller crystals orgrains by heat-treating and/or adding crystallization nucleation andgrowth stimulants (e.g., B₂O₃ and/or fluorine) to partially solutionedzones to rapidly provide recrystallization to develop the desiredcompressive stresses.

System for Manufacturing

FIG. 5A schematically illustrates a system 500 a for implementing aprocess including fusion and extrusion for forming an insulator withcompressive stresses in desired zones according to another embodiment ofthe disclosure. More specifically, in the illustrated embodiment thesystem 500 a includes a crucible 540 a that can be made from arefractory metal, ceramic, or pyrolytic graphite material. The crucible540 a can include a suitable conversion coating, or an impervious andnon-reactive liner such as a thin selection of platinum or a platinumgroup barrier coating. The crucible 540 a is loaded with a charge 541 aof a recipe as generally described above (e.g., a charge containingapproximately 25-60% SiO₂, 15-35% R₂O₃ (where R₂O₃ is 3-15% B₂O₃ and5-25% Al₂O₃), 4-25% MgO+0-7% Li₂O (where the total of MgO+Li₂O beingbetween about 6-25%), 2-20% R₂O (where R₂O is 0-15% Na₂O, 0-15% K₂O,0-15% Rb₂O), 0-15% Rb₂O and 0-20% Cs₂O, and 4-20% F), or suitableformulas for producing mica glass, such as a material with anapproximate composition of K₂Mg₅Si₈O₂₀F₄.

The crucible can heat and fuse the charge 541 a in a protectiveatmosphere. For example, the crucible 540 a can heat the charge 541 avia any suitable heating process including, for example, resistance,electron beam, laser, inductive heating, and/or by radiation fromsources that are heated by such energy conversion techniques. Aftersuitable mixing and fusion to produce a substantially homogeneous charge541 a, a cover or cap 542 a applies pressure to the charge 541 a in thecrucible 540 a. A gas source 543 a can also apply an inert gas and/orprocess gas into the crucible 540 a sealed by the cap 542 a. A pressureregulator 544 a can regulate the pressure in the crucible 540 a to causethe fused charge 541 a to flow into a die assembly 545 a. The dieassembly 545 a is configured to form a tube-shaped dielectric body. Thedie assembly 545 a includes a female sleeve 546 a that receives a malemandrel 547 a. The die assembly 545 a also includes one or morerigidizing spider fins 548 a. The formed tubing flows through the dieassembly 545 a into a first zone 549 a where the formed tubing is cooledto solidify as amorphous material and begin nucleation of fluoromicacrystals. The die assembly 545 a then advances the tubing to a secondzone 550 a to undergo further refinement by reducing the wall thicknessof the tubing to further facilitate crystallization of fluoromicacrystals.

FIG. 5B schematically illustrates a system 500 b for implementing aprocess also including fusion and extrusion for forming an insulatorwith compressive stresses in desired zones according to anotherembodiment of the disclosure. More specifically, in the illustratedembodiment the system 500 b includes a crucible 540 b that can be madefrom a refractory metal, ceramic, or pyrolytic graphite material. Thecrucible 540 b can include a suitable conversion coating, or animpervious and non-reactive liner such as a thin selection of platinumor a platinum group barrier coating. The crucible 540 b is loaded with acharge 541 b of a recipe as generally described above (e.g., a chargecontaining approximately 25-60% SiO₂, 15-35% R₂O₃ (where R₂O₃ is 3-15%B₂O₃ and 5-25% Al₂O₃), 4-25% MgO+0-7% Li₂O (where the total of MgO+Li₂Obeing between about 6-25%), 2-20% R₂O (where R₂O is 0-15% Na₂O, 0-15%K₂O, 0-15% Rb₂O), 0-15% Rb₂O and 0-20% Cs₂O, and 4-20% F), or suitableformulas for producing mica glass, such a material with an approximatecomposition of K₂Mg₅Si₈O₂₀F₄.

The system 500 b also includes a cover or cap 542 b including areflective assembly 543 b and heaters 544 b. The system 500 b can heatand fuse the charge 741 b in a protective atmosphere, such as in avacuum or with an inert gas between the crucible 540 b and the cover 542b. For example, the system 500 b can heat the charge 541 b via crucibleheaters 545 b, the cover heaters 544 b, and/or via any suitable heatingprocess including, for example, resistance, electron beam, laser,inductive heating and/or by radiation from sources that are heated bysuch energy conversion techniques. After suitable mixing and fusion toproduce a substantially homogeneous charge 541 b, the cover 542 bapplies pressure to the charge 541 b in the crucible 540 b. A gas source546 b can also apply an inert gas and/or process gas into the crucible540 b sealed by the cover 542 b at a seal interface 547 b. A pressureregulator can regulate the pressure in the crucible 540 b to cause thefused charge 541 b to flow into a die assembly 549 b. The die assembly549 b is configured to form a tube-shaped dielectric body. The dieassembly 749 b includes a female sleeve 550 b that receives a malemandrel 551 b. The die assembly 549 b can also include one or morerigidizing spider fins 552 b. The formed tubing 501 b flows through thedie assembly 549 b into a first zone 553 b where the formed tubing 501 bis cooled to solidify as amorphous material and begin nucleation offluoromica crystals.

At least a portion of the die assembly 549 b, including the formedtubing 501 b with nucleated fluoromica glass, is then rotated orotherwise moved to a position 502 b aligned with a second die assembly.A cylinder 555 b urges the formed tubing 501 b from a first zone 556 bto a second zone 557 b. In the second zone 557 b, the second dieassembly can reheat the formed tubing 501 b to accelerate crystal growthas it is further refined to continue production of preferably orientedgrains described above. The formed tubing 501 b is then advanced to athird zone 558 b to undergo further grain refinement and orientation,Selected contact areas of the third zone 558 b may be occasionallydusted or dressed with a grain nucleation accelerator, including, forexample, AlF₃, MgF₂ and/or B₂O₃. In the third zone 558 b, the formedtubing 501 b is further refined by the reduction of the wall thicknessof the formed tubing 501 b to even further facilitate crystallization offluoromica crystals and to thus generate the desired compressive forcesin areas according to the grain structures described above, along withbalancing tensile forces in areas described above. Subsequently, formedtubing 501 b, which includes the exceptionally high physical anddielectric strength formed by the compressively stressed and impervioussurfaces, can be deposited on a conveyer 559 b for moving the formedtubing 501 b.

Alternative systems and methods for producing insulative tubing withthese improved dielectric properties may utilize a pressure gradient asdisclosed in U.S. Pat. No. 5,863,326, which is incorporated herein byreference in its entirety, to develop the desired shape, powdercompaction, and sintering processes. Further systems and methods caninclude the single crystal conversion process disclosed in U.S. Pat. No.5,549,746, which is incorporated herein by reference in its entirety, aswell as the forming process disclosed in U.S. Pat. No. 3,608,050, whichis incorporated herein by reference in its entirety, to convertmulticrystalline material into essentially single crystal material withmuch higher dielectric strength. According to embodiments of thedisclosure, the conversion of multi-crystalline materials (e.g.,alumina) with only approximately 0.3 to 0.4 KV/0.001″ dielectricstrength, to single crystal materials can achieve dielectric strengthsof at least approximately 1.2 to 1.4 KV/0.001″. This improved dielectricstrength allows injectors according to the present disclosure to be usedin various applications, including for example, with high-compressiondiesel engines with very small ports into the combustion chamber, aswell as with high-boost supercharged and turbocharged engines.

According to yet another embodiment of the disclosure for forminginsulators with high dielectric strength, insulators can be formed fromany of the compositions illustrated in Table 2. More specifically, Table2 provides illustrative formula selections of approximateweight-percentage compositions on an oxide basis, according to severalembodiments of the disclosure.

TABLE 2 Illustrative Dielectric Compositions COMPOSITION D COMPOSITION R44% SO₂ 41% SO₂ 16% Al₂O₃ 21% MgO 15% MgO 16% Al₂O₃ 9% K₂O 9% B₂O₃ 8%B₂O₃ 9% F 8% F 4% K₂O

Selected substance precursors that will provide the final oxidecomposition percentages, such as the materials illustrated in Table 2,can be ball milled and melted in a covered crucible at approximately1300-1400° C. for approximately 4 hours to provide a homogeneoussolution. The melt may then be cast to form tubes that are then annealedat approximately 500-600° C. Tubes may then be further heat treated atapproximately 750° C. for approximately 4 hours and then dusted with anucleation stimulant, such as B₂O₃. The tubes may then be reformed atapproximately 1100 to 1250° C. to stimulate nucleation and produce thedesired crystal orientation. These tubes may also be further heattreated for approximately 4 hours to provide dielectric strength of atleast approximately 2.0 to 2.7 KV/0.001″.

In still further embodiments, the homogeneous solution may be ballmilled and provided with suitable binder and lubricant additives forambient temperature extrusion to produce good tubing surfaces. Theresulting tubing may then be coated with a film that contains anucleation stimulant such as B₂O₃and heat treated to provide at leastapproximately 1.9 to 2.5 KV/0.001″ dielectric strength and improvedphysical strength. Depending upon the ability to retain suitabledimensions of the tubing, including for example, the “roundness” of theextruded tubing or the profile of the tubing, higher heat treatmenttemperatures may be provided for shorter times to provide similar highdielectric and physical strength properties.

The embodiments of the systems and methods for producing the dielectricmaterials described above facilitate improved dielectric strengths ofvarious combinations of materials thereby solving the very difficultproblems of high voltage containment required for combusting low energydensity fuels. For example, injectors with high dielectric strengthmaterials can be extremely rugged and capable of operation with fuelsthat vary from cryogenic mixtures of solids, liquids, and vapors tosuperheated diesel fuel, as well as other types of fuel.

In another aspect, the high strength dielectric material embodimentsdisclosed herein also enable new processes with various hydrocarbonsthat can be stored for long periods to provide heat and power by variouscombinations and applications of engine-generator-heat exchangers foremergency rescue and disaster relief purposes including refrigeratedstorage and ice production along with pure and or safe water andsterilized equipment to support medical efforts. Low vapor pressure andor sticky fuel substances may be heated to develop sufficient vaporpressure and reduced viscosity to flow quickly and produce fuelinjection bursts with high surface to volume ratios that rapidlycomplete stratified or layered charge combustion processes.Illustratively, large blocks of paraffin, compressed cellulose,stabilized animal or vegetable fats, tar, various polymers includingpolyethylenes, distillation residuals, off-grade diesel oils and otherlong hydrocarbon alkanes, aromatics, and cycloalkanes may be stored inareas suitable for disaster response. These illustrative fuel selectionsthat offer long-term storage advantages cannot be utilized byconventional fuel carburetion or injection systems. However the presentembodiments provide for such fuels to be heated including provisions forutilization of hot coolant or exhaust streams from a heat engine in heatexchangers to produce adequate temperatures, for example betweenapproximately 150-425° C. (300-800° F.) to provide for direct injectionby injectors disclosed herein for very fast completion of combustionupon injection and plasma projection ignition.

Referring to FIG. 6, in another embodiment a fuel injector device isdisclosed. This embodiment provides: (1) up to 3000 times greater fuelflow capacity than current diesel fuel injectors to enable utilizationof low cost fuels such as landfill gas, anaerobic digester methane, andvarious mixtures of hydrogen and other fuel species along withsubstantial amounts of non-fuel substances such as water vapor, carbondioxide, and nitrogen; (2) plasma ignition of such fuel as it isprojected into the combustion chamber; and (3) replacement of dieselfuel injectors in the time of a tune-up.

Fuel injector 600 utilizes a ceramic insulator body 602 that providesdielectric containment of more than 80,000 volts at direct current tomegahertz frequencies in sections that are less than 1.8 mm (0.071″)thick between electrically conductive electrode 603 and the outersurface of insulator 602 as shown in FIGS. 600 and 602.

In instances that high frequency voltage is applied to establish ioncurrents or ion oscillation between electrodes 626 and the bore 620 ofconductive layer 603 of copper or silver may be increased by additionalplating to provide greater high frequency conductivity. In thealternative a litz wire braid may be placed over the optical fibers inthe core to reduce resistive losses.

Insulator 602 is made from a glass with the approximate composition byweight percentage of Formula 1

FORMULA 1: SiO₂ 24-48 MgO 12-28 Al₂O₃  9-20 Cr₂O₃ 0.5-6.5 F 1-9 BaO 0-14 CuO 0-5 SrO  0-11 Ag₂O   0-3.5 NiO   0-1.5 B₂O₃ 0-9

To produce the insulator 602, the composition is ball milled, melted ina suitable crucible such as a platinum, silica, magnesia, or aluminamaterial selection and extruded, compression molded, or cast into massessuitable for reheating and forming into parts of near net shape anddimensions.

In one aspect of this embodiment, a suitable composition by weight suchas set forth in Formula 2 is melted at a temperature between about 1350°C. and 1550° C. in a covered platinum, alumina, magnesia, or silicacrucible.

FORMULA 2: SiO₂ 31 MgO 22 Al₂O₃ 17 Cr₂O₃ 2.2 F 4.5 BaO 13 CuO 0.4 SrO9.5 Ag₂0 0.3 NiO 0.1

Tubular profiles can be extruded from the melt or somewhat cooledmaterial that is hot formed at temperatures between about 1050° C. and1200° C. Masses that are cast to provide the volume necessary for hotextrusion into tubing or other profiles or for forging into parts ofnear net shape and dimensions are slow cooled. Such masses are heated toa suitable temperature for hot forming such as between about 1050° C.and 1250° C. and formed by extrusion to the desired profile shapes anddimensions as may be produced through a suitable die including arefractory material such as platinum, molybdenum or graphite. Theextruded profile is dusted with one or more suitable crystallizationnucleates such as BN, B₂O₃, AlF₃, B, AlB₂, AlB₁₂ or AlN to produce agreater number of small crystals in the resulting surface zones than inthe central zones to thus reduce the volumetric packing efficiency toprovide compressive stresses in the surface zones and tensile stressesin the central zones.

Further development of compressive stresses may be produced if desiredby elongation of the crystals in the outer layers by deformation anddrag induced by the die as the extruded article is forced to form asmaller cross section, which causes such elongation.

More complex shapes and forms may be compression molded or formed in asuper alloy or graphite mold assembly that has been dusted with suitablecrystallization nucleates such as B₂O₃ or BN to produce similarcompressive stresses in near surface zones.

Previous applications desired combinations of chemical formulas and heattreatments for production of machinable material. This embodimentaccomplishes the opposite, such that it produces articles that cannot bemachined because the surface zones are too hard to be machined due tothe compressive stresses that are balanced by tensile stresses incentral section zones between or adjacent to zones with compressivestresses.

This embodiment overcomes the inherent prior art drawbacks includingproducing material that is designed to intentionally crack near zoneswhere cutting tools apply stress to enable progressive chip formation toprovide machinability. Such characteristic crack formation to allowmachinability, however, inherently allows adverse admissions ofsubstances such as organic compounds including engine lubricants,surfactants, hand fat and sweat into such cracks. Organic materialseventually tend to dehydrogenate or in other ways become carbon donorswhich then subsequently become electrically conductive pathways alongwith various electrolytes that are introduced into such cracks tocompromise the dielectric strength of the machinable ceramic article,which ultimately causes voltage containment failure. The presentembodiment remedies these drawbacks.

In another aspect of this embodiment, another suitable formula forcomponents such as insulator 602 of FIG. 6 (shown as a tube) has theapproximate weight percentages as set forth in Formula 3:

FORMULA 3 SiO₂ 30 MgO 22 Al₂O₃ 18 Cr₂O₃ 3.2 F 4.3 BaO 12 SrO 3.6 CuO 4.9Ag2O 1.3 NiO 0.1

Insulator 602 is formed with the cross section shown in FIG. 602including bore 603 and grooves or channels 604. At the zone nearest tothe combustion chamber channels 604 are closed by tapering into thediameter that elastomer tubing normally closes and seals against asshown in FIG. 604. After insulator tube 602 is extruded it is cooled toabout 650° C. by passage of hydrogen through bore 603 which reduces thecopper oxide and/or silver oxide to produce a metallic surface of copperand/or an alloy of silver and copper. After development of a suitablethickness of conductive metal 603, the outer surface of tube 602 isheated by a suitable source such as radiation from an induction heatedtube surrounding 602 or by an oxidizing flame such as a surplusoxygen-hydrogen flame and a suitable crystallization and/or finenessagent is administered to the surface to produce compressive stressesthat are balanced by tensile forces in the zone within the interior ofinsulator tube 602.

Insulator 602 may be formed as a tube by extrusion or hot forging andincludes grooves or channels 604 for fuel passage from a suitablemetering valve such as disk 606, which is normally closed againstorifices 608. Orifices 608 connect through passages 610 to an annulargroove that delivers fuel to channels 604 as shown. Orifices 608 mayhave suitable seal components such as O-rings 612 as shown to assureleak free shut off of fuel flow at times that disk 606 is in thenormally closed position against such orifices.

Suitable sleeve 618 may be a high strength polymer such aspolyamide-imide (Torlon) or a thermosetting composite with Kapton, glassfiber or graphite reinforcement or in the alternative it may be analuminum, titanium or steel alloy. Sleeve 618 includes suitable mountingfeature 616 that enables rapid clamping for replacement of thepreviously utilized diesel fuel injector in the host engine. Seal 622may be an elastomer such as a FKM, Viton or a fluorosilicone elastomerto seal 618 against the gases produced in the combustion chamber and toprevent passage of engine lubricant into the combustion chamber.

In operation, fuel is admitted through suitable fitting 652 to coolsolenoid winding 658. Just before desired fuel-injection, current isestablished in solenoid winding 658 to attract valve disk 606 away frompermanent ring-disk magnet 642. In the alternative or in addition asuitable disk spring 646 is compressed as valve 606 opens to allow fuelflow through zone 662 to pass through orifices 408 into channels 604 andto the zone past seal 622 to open elastomer sleeve 630 and allow fuel toburst into the zone between electrode 626 and the combustion chamberentry port bore through section 620 as shown in FIG. 6. Elastomer sleeve630 is normally closed against the cylindrical portion of insulator 602that extends beyond the end of grooves 604 as shown.

In applications that a solenoid assembly is chosen instead of apiezoelectric, pneumatic, hydraulic or mechanical linkage for actuationof valve 606, extremely fast acting operation of ferromagnetic valve 606is provided by application of 24 to 240 VDC to insulated winding 658.This servers the purpose of developing exceptionally high current andvalve actuation force for short times in about 3% to 21% duty cyclesdepending upon the mode of operation to enable cooling of the solenoidcomponents as a result of heat transfer to fuel that flows from fitting652 to cool winding 658 as it passes through slots or passages 607 ofvalve 606 to orifices 608 as shown.

Fuel is delivered by channels 604 to elastomeric tube valve 630 which isnormally sealed against insulator 602. Pressurization of the fuel inchannels 604 by the opening of valve 606 forces tube valve 630 open andfuel is injected into the combustion chamber through the annular openingpresented.

Suitable insulation of the copper magnet wire for such applicationsinclude polyimide varnish and aluminum plating on the copper wireselected, in which the aluminum plating is oxidized or partiallyoxidized to produce alumina. Such aluminum plating and oxidation mayalso be utilized in combination with polyimide or polyamide-imide orparylene insulation films. The assembly shown with ferromagneticcomponents 666, 650, and 662 direct the magnetic flux produced bywinding 664 through ferromagnetic valve 606 to enable very fast actionof valve 606.

Insulator 656 may be produced from any of the formulas given herein andprovides containment of high voltage applied by a suitable insulatedcable that is inserted into receiver 660 to contact conductor 603 thusproviding connection to a suitable source such as a piezoelectric orinduction transformer. Insulator 656 may be sealed against ferromagneticsleeve 650 by swaging, brazing, soldering or by a suitable sealant suchas epoxy as shown and along with insulator 602 contains ferromagneticdisks 666 and 662 as shown.

In instances that production line brazing or soldering of insulator 656to 650 is desired at contact zone 654, the corresponding contact zone of656 may be metalized by masked or otherwise localized hydrogen reductionof copper oxide and/or silver oxide such as provided in Formula 3.Alternatively a suitable metallic zone may be plated by other suitabletechnologies including sputtering or vapor deposition.

Instrumentation such as optical fibers 624 may therefore be protected byinsulator 602 through electrode portions 626 and 628 to the interface ofcombustion chamber 670 as shown in FIG. 6A.

FIG. 6B shows an alternative orientation of fuel inlet fitting 652 andarrangements for developing temperature, pressure data and delivery ofsuch data to a microprocessor by fiber optics 624 that pass through thecore of the high voltage conductor 603 as shown. High voltage suppliedby a suitable source such as a transformer, capacitor, or piezoelectricgenerator is applied through an insulated cable and dielectric boot toterminal 625 and is conducted through conductive tube or surface 603 toelectrode 626 for developing a plasma in the annular zone betweenelectrode 626 continuing to a feature 628 that is suitable forprojecting fuel into the combustion chamber in the desired pattern andwhich surrounds and protects fiber optics 624 as shown.

Alternate Embodiments

In other embodiments, the above principles can be applied to othermaterials capable of phase change, including nonceramic materials orother chemistries. For example, in any material in which a phase changemay be selectively introduced in selective zones of the material, theabove principles may be applied to induce the phase change and thusmodify the properties of the material either in the selected zones or inthe material as a whole. As such, the above principles can be applied toproduce materials with desirable properties including but not limited toinsulators. For example, in a material capable of a phase change thatwould alter the density of the material if the material was allowed toexpand in volume, the same compressive and tensive forces describedabove could be introduced into the material by selectively inducingphase changes without allowing appreciable changes in volume. In thisway, a material could be strengthened by, for example, preventing thepropagation of cracks through the material due the compressive andtensive forces in the material,

Similarly, in other materials the phase change can be used to alterother properties. For example. in a system where the phase change altersthe index of refraction, the phase change can be selectively introducedin selective zones to alter the index of refraction in those zones. Inthis way the index of refraction can be modified in a single materialacross a cross-section of the material based on the induced phasechanges. In another example., if the phase change alters the chemical orcorrosive resistance in the material, the corrosive or chemicalresistance of selected zones of the material can be modified byselectively inducing a phase change in those selected zones.

In another aspect, flame or heat processing can be used to improve theabove or other properties of the material. The flame or heat processingcan include the use of a hydrogen torch, inductive or resistive heating,or any other method known in the art, including techniques to targetspecific locations within the material to select zones for treatmentwithin the material or at the surface of the material by, for example,selecting the particular wavelength of an applied radiation.

The flame or heat processing can be used to process the surface of thematerial, including to smooth the surface to prevent stress risers thatmay weaken the material or for other advantages. For example, uponheating, surface tension due to covalent and/or ionic bonds within thematerial can cause the surface to smooth thus reducing or eliminatingstress risers or other defects on the surface of the material.

The flame or heat processing can also be used to induce a phase changein the material for the reasons set forth above. For example, if thematerial includes boron oxide, a reducing flame may be employed tocreate a boron rich zone. Then, an oxidizing flame may be employed tooxidize the boron resulting in a more effective nucleating agent and/orto enhance the ability to select the specific zone of the material fornucleation/phase change. This process can be applied to any component ofthe material susceptible to flame or heat processing, including anymetallic compound. Similarly the flame or heat processing could be usedto directly modify the material or a zone in the material depending onthe specific composition of the material or the zone. The flame or heattreatment can result in more crystal grains as set forth above, and/orimproved selection of target zones for treatment, thus further improvingmaterial endurance, dielectric strength, and/or other properties. Inanother aspect, the flame or heat treatment can be employed to preventnucleation or other changes in the flame or heat treated zone byvaporizing and/or deactivating the nucleate in the selected zone.

In other embodiments other properties can be modified by selectivelyinducing a phase change. These properties include modifications ofsurface tension, friction, index of refraction, speed of sound, modulusof elasticity and thermal conductivity.

It will be apparent that various changes and modifications can be madewithout departing from the scope of the disclosure. For example, thedielectric strength or other properties may be altered or varied toinclude alternative materials and processing means or may includealternative configurations than those shown and described and still bewithin the spirit of the disclosure.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense; that is to say, in a sense of “including,but not limited to.” Words using the singular or plural number alsoinclude the plural or singular number, respectively. When the claims usethe word “or” in reference to a list of two or more items, that wordcovers all of the following interpretations of the word: any of theitems in the list, all of the items in the list, and any combination ofthe items in the list.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of thedisclosure can be modified, if necessary, with various configurations,and concepts of the various patents, applications, and publications toprovide yet further embodiments of the disclosure.

These and other changes can be made to the disclosure in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the disclosure to thespecific embodiments disclosed in the specification and the claims, butshould be construed to include all systems and methods that operate inaccordance with the claims. Accordingly, the invention is not limited bythe disclosure, but instead its scope is to be determined broadly by thefollowing claims.

1-14. (canceled)
 15. A method of modifying one or more properties of asubstantially amorphous material comprising: providing a substantiallyamorphous material; selectively inducing a phase change in a first zoneof the material without substantially inducing a phase change in asecond zone of the material.
 16. The method of claim 15 wherein the stepof selectively inducing a phase change in a first zone of the materialcomprises inducing crystallization in the first zone.
 17. The method ofclaim 16 wherein the step of inducing crystallization comprises seedingat least a portion of the first zone.
 18. The method of claim 16 whereinthe step of inducing crystallization comprises providing a nucleatingagent to at least a portion of the first zone.
 19. The method of claim16 wherein following the step of selectively inducing a phase change ina first zone of the material, the first zone of material is undercompression and the second zone of the material is under tension. 20.The method of claim 15 wherein following the step of selectivelyinducing a phase change in a first zone of the material, the first zoneof material has an index of refraction different from the second zone ofthe material.
 21. The method of claim 15 wherein following the step ofselectively inducing a phase change in a first zone of the material, thefirst zone of material has a chemical or corrosion resistance differentfrom the second zone of the material.
 22. The method of claim 19 whereinthe material is a ceramic.
 23. The method of claim 15 wherein followingthe step of selectively inducing a phase change in a first zone of thematerial, the first zone of the material has crystalline grainssubstantially oriented to extend in a first direction to provideimproved insulating properties in a direction perpendicular to the firstdirection.
 24. The method of claim 23 wherein the first direction iscircumferential and the direction perpendicular to the first directionis radial.
 25. The method of claim 15 wherein the first zone is adjacentan outer surface of the substantially amorphous material.
 26. The methodof claim 15 wherein selectively inducing a phase change in a first zoneincludes providing an actuating agent to at least a portion of the firstzone.
 27. The method of claim 26 wherein the actuating agent is one ofB₂O₃ or fluorine.
 28. The method of claim 16, further comprising heatingthe first zone to re-solution crystals formed in at least a portion ofthe first zone as an amorphous structure, and quenching the first zoneto retain at least a portion of the amorphous structure.
 29. The methodof claim 15, further comprising heating a surface of the substantiallyamorphous material to smooth the surface.
 30. A method for forming anelectrically insulating material comprising: forming a crystallinelayered material having a first zone and a second zone, wherein thefirst zone has a lower packing efficiency than a packing efficiency inthe second zone; and forming an optical path through the electricallyinsulating material.
 31. The method of claim 30 wherein the step offorming a crystalline layered material includes formingcircumferentially aligned crystallized grains in the first zone of thelayered material, and wherein the first zone is under compression andthe second zone of the layered material is under tension.
 32. The methodof claim 30 wherein forming an optical path through the electricallyinsulating material includes providing one or more optical fibersextending longitudinally through one or more layers of the electricallyinsulating material.
 33. A method for forming a dielectric materialconfigured for use in a fuel injector, the method comprising: providinga substantially amorphous material; and crystallizing at least a portionof the substantially amorphous material to form crystalline grains thatare substantially oriented to extend in a circumferential direction toprovide improved insulating properties in a radial direction.
 34. Themethod of claim 33 wherein the step of crystallizing at least a portionof the substantially amorphous material includes retaining one or moreamorphous structures in the dielectric material.